Sharpening machine for reamers and the like



S@ T. C. DONAHUE SHARPENING MACHINE FOR REAMERS AND THE LIKE March l1 .1924.

2 Shees-Sheet 1 Filed March l. 1925 ya Vf March 11 1924.,

T. c. DONAHUE SHARPENING MACHINE FOR REAMERS ND-THE LIKE Filed March 1, 1925 ASMS 2 Sheats-Sheet 2 Patented lidar. lll, lQZl.

THOMAS C. DONAHUE, OE'PTTSEUBGH, PEIINSYLV'NIA, ASSIGNOR OF ONE-HALF TO WALTER L. JOHNSON, 0F IVICKEESOFLT, ENNSYL'VANIA.

SHAPENNG TJIACHNE EUR REAMERS AND THE 'lL-IKE.

Application led lxareh 1, 1923. .Serial NSLVGZQES.

To Usedom t may conch/rn:

Be it known that l, THOMAS C. DONAHUE, a citizen oit the United States, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Sharpening Machines for Beamers and the like, of which the following is a specilication. y

Ahis invention relates to sharpening machines and more particularly to hand operated vsharpening machines for reamers, milling cuttersand the like tools.

(lne of the principal objects is to pro vide a hand operated sharpening machine in which the angle of operation of the sharpening means may be suitably adjusted. Another object is to produce a machine O this character in which the movements of the workmans hands are guided to give the proper angle of stroke to the sharpening tool. A. 'further object is to provide a machine which is adapted to sharpen reamers or milling` cutters of various diametersand lengths. Still another object of this invention is to provide means for substantially micrometric adjustment of the so-ealled clearance or relief o1c the cutting edges of said reamers or milling cutters. Still a further object is to provide a machine wherein sharpening means of various ,i sizes may be used andquickly installed. Addi tional objects and features of this invention will appear from the `'following description ltaken in connection with the accompanying drawings.

ln the drawings:

Fig..1 is a top plan view of my complete sharpening machine in working condition.

Fig. 2 is a side elevation of the complete machine, corresponding to Fig. 1.

Fig. 3 is an enlarged view of the sharpening means showing the method of mounting it as well as its adjustable guide-support.

Fig. 4 is an end elevation ot the complete machine, corresponding especially to Fig. 2.

Fig. 5 is a cross-sectional view of the adjust-able Vclamp for the sharpening means.

Fig. 6 is an end View corresponding to Fig. 5.

Fig. 7 is a fragmentary View showing the end of a guide-rod used in my machine. Fig. -8 is an end-view Correspending to Fig.

Fig. 9 is an end-view et `an adjustable support used in my machine.

Figs. 10, l1 and 12 are diagrammatic views showing the method of linal adjustment of the cutting edges oi a reamer yor milling-cutter.

Referring to the drawings, my sharpening machine comprises a table 1 havin legs 2 of suitable height, a head-stock 3 and atailstock intermediate these stocks, and secured on one side of the table is an arm 5, the top of which is preferably made level with the top oi^` table 1. The head-stock is furnished Awith a. lined center 6 secured therein by a set-screw 7. rIhe tail-stock is provided with a threaded spindle 8 having at the inner end the center 9 and at the outer end the hand-wheel 10, whereby the center 9 may be moved in or out, to accommodate various lengths ot reamers or milling-cutters. ln theligures the invention has been shown as appliedto an adjustable reamer l, for which purpose the machine is mostly used. Both stocks are longitudinally movableonthe table and are held in the desired positions by meansof the studbol'ts 12 and 13, engaging slots 14 and 15 in table 1, and by the 'ing-nuts 16.

Upon the arm i is slidably mounted `a standard 17 held thereon by the large headed guide-screw 1S screwed partly inthe base of the standard and having an enlarged `portion 19 which snugly lits into a finished slot 2O cut in said arm. This standard can be moved back `and forth by means of the l`eed-screw 21 which is threaded into an upwardly directed lug 22 situated at the end of the arm 5 and preferably cast integral therewith. This feedscrew is secured lor rotation to the standard in any desired manner, tor instance b v means of a pin 23, driven into the circular boss 24 on the standard, and engaging a groove 25 out in the smooth end 26 of the feed-screw.

Mounted centrally of the standard and vertically adjustable therein by means et a setscrew 27 is the adjustable rest 28 having. the cylindrical body portion 29 and a head 30. This head has a drilled aperture 3 1, a sawcut slot 32, a threaded stud S3 and a wingnut 34, by means of which a rest-bar 35 may be supported and clamped in any desired position. Y

The rest-bar is substantially l -sliaped and carries at the end of its long and horizontal leg 36 a push-blade 37 made of resilient material and secured therein by the rivets 38.l rl`he shorter and vertical leg 39 of the rest-bar terminates with a slightly reduced portion i0 in which a groove ll has been cut. Upon this portion is mounted for rotation in a horizontal plane the swivelguide 4t2 comprising a head et?) and a shank portion 44. 'lhe latter is partly drilled vertically to receive the reduced port-ion Ll0 to which it is secured against escape by means of a set-screw 45 engaging the aforementioned groove Lll.

in the head i3 of the swivel-guide is drilled the horizontal aperture i6 which is slidably engaged by a guide-rod el? of suitable length, having at its forward end a downwardly directed and flattened head 48, preferablyl provided with inwardly pointing prongs e9.

-The sharpening means, such as a file, or

the carborundum slab is secured to the underside of the guide-rod l? by the agency of the specially designed clamp 5l. ils particularly disclosed in ligs. 3, 5 and 6, this clamp comprises an elongated body 52 provided with a loi'igitudinal aperture 53 of sufficient uniform width to permit a sliding fit for the guide-rod. 'lhe rear end 54 of the aperture is preferably made circular with a bead 55 at its lower circumference. The sei'ni-circular top part of the aperture is horizontal, whereas the bottom part is made forwardly declining so that the front end 56 of the aperture will assume the elongated form shown in Fig. 6. Centrally positioned and longitudinally spaced on the clamp are the set-screw 5i" and the clamping thumb-screw 58, the purpose of which is ei:- plained herebelow. The front endV of the clamp is also provided near the bottom with the outwardly directed prongs 59.

rlhe clamping of the carborundum slab is done as follows: rihe slab 50 is first placed symmetrically under the guide-rod l? with its forward end bearing against the prongs 49. lhe clamp 5i is now slid forward on the guide-rod until the prongs 59 barely touch the rear end of the carboruiuluni slab. The set-screw 5"? is now forced somewhat into the guide-rod and the slab finally solidly fixed between both sets of prongs by forcing the tliuinbscrew downward. rlhis will cause the forward end of the c amp to describe an arcuate movement upwardly,

with the set-screw 57 as a center or fulcrum, thereby forcing prongs 59 into the carborun-` dum slab and holding it rigidly in place.

To remove the slab, it is not necessary to unloosen the set-screw 57, it suices to partly unscrew the thumb-screw 58, thereby allowing the forward end of the clamp to drop, thus sepa-rating the prongs from the carborundum slab. Y

rlhe preceding detailed description of my invention, taken in connectionwith the drawings will malte the method of using the niachine easily understood; it isY as follows: The tool to be sharpened, for instance the adjustable reanier il, is placed and ratherl firmly held between the centers 6 and 9; the head and tail-stocks haying first been suitably chunped on the table to bring the middle of the cutting part of the reen-ier substantially in line with the center of the standard l?. The carborundrun'slab is then adjusted to set level upon the blade il@ of the reamer and the end of the push-blade is brought to bear against theV near side of the blade lla; see i9. 'lh rest-bar now clamped in the adjustable rest 28 and the exact amount of clearance or relief is obtained by forcing the push-blade forward by means of the feed-screw rlhe reamer is now firmly clamped between the centers 6 and 9 and the sharpening of the blade lliL is obtained by manuallyY passing the carborundum slab bacl and forth overV it. Fig. ll shows in dot and dash lines how, by moving forward the push-blade, the top of blade il is ground olil at the baci; to produce the desired elearance. Fig. l2 shows the shape of the finished blade and the arrow indicating the operating direction of the reamer. The saine operations are repeated for. each blade of the reamer.

is will be understood, as suggested herein there may be slight changes made'in the construction and arrangement of the details of my invention without departing from the field and scope of the saine, and l intend to include all such variations as fall within the scope of the appended claims, in this application in which the preferred form only of invention is disclosed. It will also be noted that in said claims mentionv is made only, for the salie of brevity, of the use of this machine for sharpening reamers; but it is understood that these claims are to be read as Vincluding milling-cutters, all suitable types of reamcrs and similar tools.

lWhat l claim is: Y Y

l. ln a sharpeningmachine of the character described, the combination of axially aligned centersupports for supporting the tool to be sharpened; manually operated reciprocating sharpening means; a guide rod therefor; adjustable means for securing said sharpening means to said guide-rod; a restbar disposed rectangularly to the axis of said center supports having a horizontal and a vertical portion; a horizontally rotatable guide for said guide-rod mounted upon the vertical portion of said rest-bar; a vertically adjustable rest for said rest-bar; a flexible pushblade secured and positioned at the end of the horizontal portion of said rest-bar and means for moving said rest-bar at right angles to the axis of said center supports for imparting to the tool to be sharpened a fractional part of a revolution required for producing the desired relief on the cutting edge of said tool.

2. ln a sharpening machine of the character described, the combination of axially aligned center supports for supporting the tool to be sharpened; manually operated reciprocating sharpening means; a guidenod therefor; clamping means slidably mounted upon said guide-rod for securing said sharp*- ening means thereto; means for releasing said sharpening means from said guide-rod Without longitudinally displacing said clamp ing means; a rest-bar disposed rectangula-rly to the axis of said center supports having a horizontal and a vertical portion; a horizontally rotatable guide-rod mounted upon the vertical portion of said rest-bar; vertically adjustable rest for said rest-bar; a flexible push-blade secured and positioned at the end of the horizontal portion of said restwbar and means for moving said rest bar at right angles to the axis of said center supports for imparting to the tool to be sharpened a fractional part of a revolution required for producing the desired relief on the cutting edges of said tool.

8. In a sharpening machine of the character described, the combination of axially aligned center supports for supporting the tool to be sharpened; manually operated reciprocating sharpening means; a guide-rod therefor; clamping means slidably mounted upon said guide-rod for securing said sharpening means thereto; means for releasing said sharpening means from said guiderod Without longitudinally displacing said clamping means; the latter comprising a sleeve-member having an aperture of uniform Width and level at the top but of varying depth increasing towards the sharpening means clamped thereby, said aperture being engaged by said guide-rod; a set-screwv positioned above and adjacent the small end of said aperture in said clamping means for securing the saine on said guide-rod against longitudinal displacement, and another screw positioned above and adjacent the larger end of said aperture for arcuately moving said clamping means around said set-screw as a fulcruin; a rest-bar disposed rect-angularly to the axis of said center supports having a horizontal and a vertical portion; a horizontally rotatable guide for said guide-rod mounted upon the vertical portion of said rest-bar; a vertically adjustable rest for said rest-bar; a flexible push-blade secured and positioned at the end of the hori zontal portion of said rest-bar; and means for moving said rest-bar at right angles to the axis of said center supports for imparting to the tool to be sharpened a fractional part of a revolution required for producing the desired relief on the cutting edges of said tool.

ln testimony whereof I affix my signature.

THOMAS C. DONAHUE. 

